This invention relates to an arm apparatus for mounting electronic devices and a method for manufacturing the arm apparatus, and more specifically to an extension arm suitable to mount a flat-screened electronic peripheral device, such as a computer monitor or television and the method for manufacturing the extension arm.
Adjustable extension arms for mounting electronic peripheral devices, such as a computer monitor or a television, are well known in the prior art. However, due to recent advances in flat-screen technology, there is a demand for adjustable extension arms that are particularly suited for use with flat-screen devices, such as flat screen computer monitors and televisions.
FIGS. 1–7 are assembly drawings of an extension arm 10 for mounting a peripheral device, in accordance with the prior art. As shown in FIG. 1, the main elements of the extension arm 10 are a first end cap 12, an upper channel 14, a lower channel 16, a second end cap 18, and a forearm extension 20. The first end cap 12 has an end cap shaft 22 that is pivotably attachable to a rigid support mount (not shown), such as an orifice sized to accept the end cap shaft 22 or a track configured and sized to engage the grooves on end cap shaft 22. The first end cap 12 is pivotably coupled via pins 24 to both the upper channel 14 and the lower channel 16. The opposite ends of the upper channel 14 and the lower channel 16 are pivotably coupled via pins 24 to the second end cap 18. The second end cap 18 is coupled to the forearm extension 20 via a forearm extension pin 92. The forearm extension 20 has a vertically disposed hole 26 therethrough for accepting a device mount (not shown) such as a tilter, platform or other apparatus. The combination of the upper and the lower channels 14, 16 and the first and the second end caps 12, 18 form an adjustable parallelogram that permits a device coupled to the forearm extension 20 to be raised and lowered to a desirable height. The parallelogram retains its position by employing a gas spring 28, which is pivotably and adjustably attached to the first end cap 12 and the upper channel 14, as will be further described below. Generally, the gas spring 28 is sized so as to have a fixed length until an upward or downward force is exerted at the second end cap 18 that exceeds the gas spring's designed resistance. Thus, the gas spring 28 causes the parallelogram to retain its position when the only force exerted at the second end cap 18 is the weight of the device, but permits the parallelogram to be adjusted when a user pushes the device coupled to the forearm extension 20 up or down.
FIG. 2 illustrates a side view of the first end cap 12, having the end cap shaft 22 disposed on a first end 30 of the first end cap 12. To provide a rigid connection between the two pieces, the end cap shaft 22 is typically machined from steel and is inserted into the first end 30 during the casting process of the first end cap 12. The end cap shaft 22 has a hole 32 formed in an end of the end cap shaft 22 that is inserted into the first end cap 12. The first end cap 12 is typically fabricated from cast aluminum. The first end cap 12 also has a second end 34 having a hole 36 disposed therethrough. Disposed within the first end cap 12 is a threaded rod 38. A first end 40 of the threaded rod 38 is inserted into the hole 32 at the base of the end cap shaft 22. A second end 42 of the threaded rod 38 is aligned with the hole 36 and is held in place by a clip 44. The clip 44 is fastened to an inner surface of the first end cap 12 by screws 46.
Threadedly mounted on the threaded rod 38 is a clevis 48. FIG. 3 illustrates a sideview of the clevis 48 including a tapped hole 50 in the center thereof. The tapped hole 50 receives the threaded rod 38, as shown in FIG. 2. At a first end of the clevis 48 is a pair of fastening members 52, 54 to which are fastened one end of the gas spring 28. A second end 56 of the clevis 48 is configured to slidably engage a track 58 which is integrally molded in the first end cap 12 (see FIG. 2). The second end 42 of the threaded rod 38 is configured to be engaged by a hex-shaped key which is inserted through the hole 36 when the second end 42 is properly aligned with the hole 36. The hex-shaped key is employed so as to rotate the threaded rod 38 along its axis of rotation. When the threaded rod 38 is rotated along its axis of rotation, the clevis 48 moves along the length of the threaded rod 38 in a direction that corresponds to the direction which the hex-shaped key is turned. This movement of the clevis 48 permits the gas spring 28 to be adjusted.
FIGS. 4(a) and 4(b) illustrate the upper channel 14, which comprises channel bottom 60 from which extend two channel sidewalls 62. Channel bottom 60 and sidewalls 62 are typically stamped from 13 gauge steel sheet in order to give the upper channel 14 a desired degree of structural rigidity. At each of the ends of the channel bottom 60, a semi-circular region 64 of the sidewalls 62 is cut out to accommodate cold-rolled steel rollers 66, which have a hole 68 therethrough for receiving the pins 24. The rollers 66 are rigidly attached to the upper channel 14 by MIG welding along the edge of the semi-circular cut out region 64 and along the ends of the channel bottom 60.
Additionally, the upper channel 14 comprises stiffener 70, which is welded to an inner surface of the channel bottom 60. Besides providing additional structural rigidity to the upper channel 14, the stiffener 70 has a hole disposed at one end with a threaded ball stud 72 placed within the hole and fixed in place by a nut 74. The ball stud 72 is configured and sized to receive one end of the gas spring 28. The longitudinal centerline 76 of the upper channel 14 is illustrated in FIG. 4(b).
FIGS. 5(a) and 5(b) illustrate the lower channel 16 which comprises a channel bottom 78 from which extend two channel sidewalls 80. As with the upper channel 14, the channel bottom 78 and sidewalls 80 are typically stamped from 13 gauge steel sheet, which is relatively heavy in order to give the lower channel 16 a desired degree of structural rigidity. At opposite ends of the channel bottom 78, a semi-circular region 82 of the sidewalls 80 is cut out to accommodate cold-rolled steel rollers 84, which have a hole 86 therethrough for receiving the pins 24. The rollers 84 are rigidly attached to the lower channel 16 by MIG welding along the edge of the semi-circular cut out region 82 and along the ends of the channel bottom 78. The longitudinal centerline 88 of the lower channel 16 is illustrated on FIG. 5(b)
FIG. 6 illustrates the second end cap 18. Unlike the first end cap 12, the second end cap 18 does not have an end cap shaft, nor does it have a clevis assembly for attachment to the gas spring 28. Instead, the second end cap 18 has a hole 90 disposed in a bottom end for receiving the forearm extension pin 92, and a hole 94 in a side for inserting a pin 96 into the forearm extension pin 92, as illustrated in FIG. 1.
FIG. 7 illustrates the forearm extension 20 having the forearm extension pin 92 welded thereto. The forearm extension pin 92 has a hole 98 formed in an upper end to receive the pin 96. The forearm extension 20 is configured to be pivoted around the forearm extension pin 92, and is held in place within the second end cap 18 by the pin 96 which penetrates the hole 94 of the second end cap 18 and the hole 98 of the forearm extension pin 92.
Extension arms 10 of the prior art, such as the one shown in FIGS. 1–7 and others like it, are ill-suited for flat-screen monitors and televisions, in that they are bulky and cumbersome. In addition, due to the configuration of its various parts, extension arms 10 of the prior art cannot be flattened against a mounting surface so that the entire extension arm 10 is hidden behind the flat screen device when the device is substantially flush with the mounting surface. Additionally, the extension arms 10 of the prior art are costly to manufacture and difficult to assemble.
Thus, there is a need for an extension arm suitable to mount a flat-screened electronic peripheral device, such as a computer monitor or television, that is inexpensive and easy to manufacture and assemble, and that permits a flat-screen device to be mounted substantially flush with the mounting surface.